<div dir="auto"><div>LllllllllljllLllllll<br><div class="gmail_extra"><br><div class="gmail_quote">Em 04/09/2017 13:50, "João Costa &gt; CT1FBF" <<a href="mailto:ct1fbf@gmail.com">ct1fbf@gmail.com</a>> escreveu:<br type="attribution"><blockquote class="quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">The Bouvet Island 160m Vertical<br>
<br>
Tim Duffy, K3LR, reports: The DX Engineering and Bouvet Island teamsl<br>
have worked together to design an efficientllll 90 foot top loaded 160<br>
meter vertical antenna that can be installed quickly and sallllflely on<br>
Bouvet Ijsland by the 3Y0Z team this Janulteamslnullllaryllllllllllllll a good radial system the difference in gain between a 120 ft<br>
(fulll quarter wavelength) vertical and this l 90 foot top loaded<br>
vertical is less than 0.5 dB.<br>JLlll vertical uses a custom designed heavy duty hinged pivot base with<br>
blase insulators to accommodate a 40 foot falling derrick 3 inch heavy<br>
duty pipe for installation.<br>
<br>
The vertical is base fed using two inductors to match to 50 ohms. The<br>
first 70 feet of the vertical is Universal Aluminum tower (12 inch<br>
face) and the top 20 feet is 1.875 inch diameter aluminum tubing.<br>
<br>
There are guys at 30, 50 and 70 feet. There are also three 30 foot top<br>
loading wires attached to the top of the tubing that are tied to<br>
anchors<br>
60 feet out from the base.<br>
<br>
DXE is actually donating two of these vertical packages to the 3Y0Z<br>
team in case one gets damaged (there are 300 storms per year on<br>
Bouvet).<br>
<br>
More details on the construction and the final test raising plus VSWR<br>
measurements are shown in the video filmed and produced (in 4K Ultra)<br>
by Greg, W8WWV. <a href="https://www.youtube.com/watch?v=bSw-0TjaUiU" rel="noreferrer" target="_blank">https://www.youtube.com/watch?<wbr>v=bSw-0TjaUiU</a><br>
<br>
OPDX<br>
<br>
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